Mobile terminal and controlling method thereof

ABSTRACT

A digital television including a display unit configured to display a keypad including a plurality of key buttons which are assigned with different alphabet characters, respectively, and a text window; and a controller configured to receive a first signal selecting a first key button of the plurality of key buttons, display a first alphabet character assigned with the first key button in the text window, and display a first sub key button assigned with a second alphabet character on a first region adjacent to the first key button of the keypad, in response to the first signal, and receive a second signal selecting the first sub key button, and display the second alphabet character next to the first alphabet character in the text window, and display a second sub key button assigned with a third alphabet character on the first region adjacent to the first key button of the keypad, in response to the second signal. The second alphabet character is predicted as a next character of the first alphabet character, and the third alphabet character is predicted as a next character of the first and second alphabet characters.

CROSS REFERENCE TO THE RELATED APPLICATIONS

This application is a Continuation of co-pending application Ser. No.14/088,135, filed on Nov. 22, 2013, which is a Continuation of U.S.application Ser. No. 12/824,068, filed on Jun. 25, 2010 (now U.S. Pat.No. 8,612,885 B2), which claims priority under 35 U.S.C. §119(a) toApplication No. 10-2009-0111310, filed in Korea on Nov. 18, 2009, all ofwhich are hereby expressly incorporated by reference into the presentapplication.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to a mobile terminal and correspondingmethod of controlling a mobile terminal.

Discussion of the Related Art

A mobile terminal can perform various functions such as data and voicecommunications, capturing images and video via a camera, recordingaudio, playing music files and outputting music via a speaker system,displaying images and video on a display, playing games, etc. Thus,mobile terminals now function as multimedia players. More recently,mobile terminals have been configured to receive broadcast and multicastsignals which permit viewing of contents, such as videos and televisionprograms.

Further, many mobile terminals include touchscreens that allow a user toinput information by touching the display. Many users thus now inputtext messages and other data by touching a keypad displayed on thetouchscreen. However, the keypad has key buttons of which number or sizeis smaller than those of a general personal computer. Thus, the user isoften inconvenienced when using the keypad on mobile terminals.

SUMMARY OF THE INVENTION

Accordingly, one object of the present invention is directed to a mobileterminal and controlling method thereof that substantially obviate oneor more problems due to limitations and disadvantages of the relatedart.

Another object of the present invention is to provide a mobile terminaland controlling method thereof, by which a terminal user is furtherfacilitated to input characters via a keypad provided to a mobileterminal having key buttons of which number or size is smaller than thatof key buttons provided to a keyboard of a personal computer.

To achieve these objects and other advantages and in accordance with thepurpose of the invention, as embodied and broadly described herein, thepresent invention provides in one aspect a mobile terminal including atouchscreen configured to display a keypad including a plurality of keybuttons having intrinsic alphabets, respectively, and a controller, if adesired one of a plurality of the key buttons is first touched,controlling the intrinsic alphabet of the desired key button to beinput, predicting a recommended word starting with a first alphabetequal to the intrinsic alphabet of the desired key button, and if thedesired key button is second touched after having been first touched,controlling a second alphabet of the recommended word to be input.

In another aspect, the present invention provides a method ofcontrolling a mobile terminal and which includes displaying a keypadincluding a plurality of key buttons corresponding to intrinsicalphabets, respectively, on a touchscreen, if a desired one of aplurality of the key buttons is first touched, inputting the intrinsicalphabet of the desired key button, predicting a recommended wordstarting with a first alphabet equal to the intrinsic alphabet of thedesired key button, and if the desired key button is second touchedafter having been first touched, inputting a second alphabet of therecommended word.

In still another aspect, the present invention provides a mobileterminal including a touchscreen configured to display a keypadincluding a plurality of key buttons having assigned first alphabetcharacters, respectively, and a controller configured to receive a firstkey input of a first key button of the plurality of key buttons, todisplay a first alphabet character corresponding to the first key inputon a display portion of the mobile terminal, to predict a word thatstarts with the first alphabet character, to receive a second key inputof the first key button after the first key input, and to display asecond alphabet character included in the predicted word on the displayportion based on the second key input.

In another aspect, the present invention provides a method ofcontrolling a mobile terminal, and which includes displaying, on atouchscreen of the mobile terminal, a keypad including a plurality ofkey buttons having assigned first alphabet characters, respectively;receiving, via a controller on the mobile terminal, a first key input ofa first key button of the plurality of key buttons; displaying, on adisplay portion of the mobile terminal, a first alphabet charactercorresponding to the first key input; predicting, via the controller, aword that starts with the first alphabet character; receiving, via thecontroller, a second key input of the first key button after the firstkey input; and displaying, on the display portion, a second alphabetcharacter included in the predicted word based on the second key input.

It is to be understood that both the foregoing general description andthe following detailed description of the present invention areexemplary and explanatory and are intended to provide furtherexplanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this application, illustrate embodiment(s) of the invention andtogether with the description serve to explain the principle of theinvention. In the drawings:

FIG. 1 is a block diagram of a mobile terminal according to oneembodiment of the present invention;

FIG. 2A is a front perspective diagram of a mobile terminal according toone embodiment of the present invention;

FIG. 2B is a rear perspective diagram of a mobile terminal according toone embodiment of the present invention;

FIG. 3 is a flowchart illustrating a method of controlling a mobileterminal according to an embodiment of the present invention; and

FIGS. 4 to 16D are different display screens illustrating a method ofcontrolling a mobile terminal according to an embodiment of the presentinvention is implemented.

DETAILED DESCRIPTION OF THE INVENTION

Hereinafter, a mobile terminal relating to embodiments of the presentinvention will be described below in more detail with reference to theaccompanying drawings. Further, the mobile terminal described in thespecification can include a cellular phone, a smart phone, a laptopcomputer, a digital broadcasting terminal, personal digital assistants(PDA), a portable multimedia player (PMP), a navigation system and soon.

FIG. 1 is a block diagram of a mobile terminal 100 according to anembodiment of the present invention. As shown, the mobile terminal 100includes a radio communication unit 110, an audio/video (A/V) input unit120, a user input unit 130, a sensing unit 140, an output unit 150, amemory 160, an interface 170, a controller 180, and a power supply 190.Not all of the components shown in FIG. 1 are essential parts and thenumber of components included in the mobile terminal can be varied.

In addition, the radio communication unit 110 includes at least onemodule that enables radio communication between the mobile terminal 100and a radio communication system or between the mobile terminal 100 anda network in which the mobile terminal 100 is located. For example, inFIG. 1, the radio communication unit 110 includes a broadcastingreceiving module 111, a mobile communication module 112, a wirelessInternet module 113, a local area communication module 114 and aposition information module 115.

The broadcasting receiving module 111 receives broadcasting signalsand/or broadcasting related information from an external broadcastingmanagement server through a broadcasting channel. Further, thebroadcasting channel can include a satellite channel and a terrestrialchannel. Also, the broadcasting management server can be a server thatgenerates and transmits broadcasting signals and/or broadcasting relatedinformation or a server that receives previously created broadcastingsignals and/or broadcasting related information and transmits thebroadcasting signals and/or broadcasting related information to aterminal. The broadcasting signals can include not only TV broadcastingsignals, radio broadcasting signals and data broadcasting signals, butalso signals in the form of a combination of a TV broadcasting signaland a radio broadcasting signal.

In addition, the broadcasting related information can be information ona broadcasting channel, a broadcasting program or a broadcasting serviceprovider. The broadcasting related information can be provided eventhrough a mobile communication network. In this instance, thebroadcasting related information can be received by the mobilecommunication module 112. The broadcasting related information can alsoexist in various forms. For example, the broadcasting relatedinformation can exist in the form of an electronic program guide (EPG)of the digital multimedia broadcasting (DMB) system or in the form of anelectronic service guide (ESG) of the digital video broadcast-handheld(DVB-H) system.

In addition, the broadcasting receiving module 111 receives broadcastingsignals using various broadcasting systems. In particular, thebroadcasting receiving module 111 can receive digital broadcastingsignals using digital broadcasting systems such as the digitalmultimedia broadcasting-terrestrial (DMB-T) system, the digitalmultimedia broadcasting-satellite (DMB-S) system, the media forward linkonly (MediaFLO) system, and the DVB-H and integrated services digitalbroadcast-terrestrial (ISDB-T) system. The broadcasting receiving module111 can also be constructed to be suited to broadcasting systemsproviding broadcasting signals other than the above-described digitalbroadcasting systems. The broadcasting signals and/or broadcastingrelated information received through the broadcasting receiving module111 can also be stored in the memory 160.

Further, the mobile communication module 112 transmits/receives a radiosignal to/from at least one of a base station, an external terminal, anda server on a mobile communication network. The radio signal can includea voice call signal, a video telephony call signal or data in variousforms according to transmission and receiving of text/multimediamessages. The wireless Internet module 113 corresponds to a module forwireless Internet access and can be included in the mobile terminal 100or externally attached to the mobile terminal 100. Wireless LAN (WLAN)(Wi-Fi), wireless broadband (Wibro), world interoperability formicrowave access (Wimax), high speed downlink packet access (HSDPA) andso on can be used as a wireless Internet technique. The local areacommunication module 114 corresponds to a module for local areacommunication. Bluetooth, radio frequency identification (RFID),infrared data association (IrDA), ultra wideband (UWB) and ZigBee can beused as a local area communication technique.

In addition, the position information module 115 confirms or obtains theposition of the mobile terminal 100. A global positioning system (GPS)module is a representative example of the position information module115. Further, the GPS module 115 can calculate information on distancesbetween one point (object) and at least three satellites and informationon the time when the distance information is measured and applytrigonometry to the obtained distance information to obtainthree-dimensional position information on the point (object) accordingto latitude, longitude and altitude coordinates at a predetermined time.Furthermore, a method of calculating position and time information usingthree satellites and correcting the calculated position and timeinformation using another satellite is also used. In addition, the GPSmodule 115 continuously calculates the current position in real time andcalculates velocity information using the position information.

Referring to FIG. 1, the A/V input unit 120 is used to input an audiosignal or a video signal and includes a camera 121 and a microphone 122.The camera 121 processes image frames of still images or moving imagesobtained by an image sensor in a video telephony mode or a photographingmode. The processed image frames can be displayed on a display 151included in the output unit 150. In addition, the image frames processedby the camera 121 can be stored in the memory 160 or transmitted to anexternal device through the radio communication unit 110. The mobileterminal 100 can also include at least two cameras according toconstitution of the terminal.

Further, the microphone 122 receives an external audio signal in a callmode, a recording mode or a speed recognition mode and processes thereceived audio signal into electric audio data. The audio data can alsobe converted into a form that can be transmitted to a mobilecommunication base station through the mobile communication module 112and output in the call mode. The microphone 122 can employ various noiseremoval algorithms for removing noise generated when the external audiosignal is received.

In addition, the user input unit 130 receives input data for controllingthe operation of the terminal from a user. The user input unit 130 caninclude a keypad, a dome switch, a touch pad (constantvoltage/capacitance), jog wheel, jog switch and so on. The sensing unit140 senses the current state of the mobile terminal 100, such as anopen/close state of the mobile terminal 100, the position of the mobileterminal 100, whether a user touches the mobile terminal 100, thedirection of the mobile terminal 100 and acceleration/deceleration ofthe mobile terminal 100 and generates a detection signal for controllingthe operation of the mobile terminal 100. For example, the sensing unit140 can sense whether a slide phone is opened or closed when the mobileterminal 100 is the slide phone. Furthermore, the sensing unit 140 cansense whether the power supply 190 supplies power and whether theinterface 170 is connected to an external device. The sensing unit 140also includes a proximity sensor 141 in FIG. 1.

In addition, the output unit 150 generates visual, auditory or tactileoutput and in FIG. 1 includes the display 151, an audio output module152, an alarm 153, a haptic module 154, and a projector module 155. Thedisplay 151 displays information processed by the mobile terminal 100.For example, the display 151 displays a UI or graphic user interface(GUI) related to a telephone call when the mobile terminal is in thecall mode. The display 151 also displays a captured or/and receivedimage, UI or GUI when the mobile terminal 100 is in the video telephonymode or the photographing mode.

The display 151 can also include at least one of a liquid crystaldisplay, a thin film transistor liquid crystal display, an organiclight-emitting diode display, a flexible display and a three-dimensionaldisplay. Some of these displays can be of a transparent type or a lighttransmission type, which is referred to as a transparent display. Thetransparent display also includes a transparent liquid crystal display.The rear structure of the display unit 151 can also be of the lighttransmission type. According to this structure, a user can see an objectlocated behind the body of the mobile terminal 100 through an area ofthe body of the mobile terminal 100, which is occupied by the display151.

Further, the mobile terminal 100 can include at least two displays 151according to constitution of the terminal. For example, the mobileterminal 100 can include a plurality of displays that are arranged on asingle face at a predetermined distance or integrated. Otherwise, theplurality of displays can be arranged on different sides. In addition,when the display 151 and a sensor sensing touch (referred to as a touchsensor hereinafter) form a layered structure, which is referred to as atouch screen hereinafter, the display 151 can be used as an input devicein addition to an output device. The touch sensor can be in the form ofa touch film, a touch sheet and a touch pad, for example.

Also, the touch sensor can be constructed such that it converts avariation in pressure applied to a specific portion of the display 151or a variation in capacitance generated at a specific portion of thedisplay 151 into an electric input signal. The touch sensor can also beconstructed such that it can sense pressure of touch as well as theposition and area of touch. When touch input is applied to the touchsensor, a signal corresponding to the touch input is transmitted to atouch controller. The touch controller then processes the signal andtransmits data corresponding to the processed signal to the controller180. Accordingly, the controller 180 can detect a touched portion of thedisplay 151.

Referring to FIG. 1, the proximity sensor 141 can be located in aninternal region of the mobile terminal 100, surrounded by the touchscreen, or near the touch screen. The proximity sensor 141 senses anobject approaching a predetermined sensing face or an object locatednear the proximity sensor 141 using an electromagnetic force or infraredrays without having mechanical contact. Further, the proximity sensor141 has a lifetime longer than that of a contact sensor and has wideapplication. The proximity sensor 141 also includes a transmission typephoto-electric sensor, a direct reflection type photo-electric sensor, amirror reflection type photo-electric sensor, a high-frequencyoscillating proximity sensor, a capacitive proximity sensor, a magneticproximity sensor, an infrared proximity sensor, etc.

In addition, a capacitive touch screen is constructed such that aproximity of a pointer is detected through a variation in an electricfield according to the proximity of the pointer. In this instance, thetouch screen (touch sensor) can be classified as a proximity sensor. Forconvenience of explanation, an action of approaching the pointer to thetouch screen while the pointer is not in contact with the touch screensuch that the location of the pointer on the touch screen is recognizedis referred to as a “proximity touch” and an action of bringing thepointer into contact with the touch screen is referred to as a “contacttouch” in the following description. Also, a proximity touch point ofthe pointer on the touch screen means a point of the touch screen towhich the pointer corresponds perpendicularly to the touch screen whenthe pointer proximity-touches the touch screen.

Further, the proximity sensor 141 senses a proximity touch and aproximity touch pattern (for example, a proximity touch distance, aproximity touch direction, a proximity touch velocity, a proximity touchtime, a proximity touch position, a proximity touch moving state, etc.).Information corresponding to the sensed proximity touch action andproximity touch pattern can also be displayed on the touch screen.

Also, the audio output module 152 can output audio data received fromthe radio communication unit 110 or stored in the memory 160 in a callsignal receiving mode, a telephone call mode or a recording mode, aspeech recognition mode and a broadcasting receiving mode. The audiooutput module 152 also outputs audio signals related to functions (forexample, a call signal incoming tone, a message incoming tone, etc.)performed in the mobile terminal 100. The audio output module 152 caninclude a receiver, a speaker, a buzzer, etc.

The alarm 153 outputs a signal for indicating a generation of an eventof the mobile terminal 100. Examples of events generated in the mobileterminal 100 include receiving a call signal, receiving a message,inputting a key signal, inputting touch, etc. The alarm 153 can alsooutput signals in forms different from video signals or audio signals,for example, a signal for indicating a generation of an event throughvibration. The video signals or the audio signals can also be outputthrough the display unit 151 or the audio output module 152.

In addition, the haptic module 154 generates various haptic effects thatthe user can feel. A representative example of the haptic effects isvibration. The intensity and pattern of vibration generated by thehaptic module 154 can also be controlled. For example, differentvibrations can be combined and output or sequentially output. The hapticmodule 154 can also generate a variety of haptic effects including aneffect of stimulus according to an arrangement of pins vertically movingfor a contact skin face, an effect of stimulus according to a jet forceor sucking force of air through a jet hole or a sucking hole, an effectof stimulus of rubbing the skin, an effect of stimulus according tocontact of an electrode, an effect of stimulus using an electrostaticforce and an effect according to reproduction of cold and warmth usingan element capable of absorbing or radiating heat in addition tovibrations. Further, the haptic module 154 can not only transmit hapticeffects through direct contact but also allow the user to feel hapticeffects through kinesthetic sense of his or her fingers or arms. Themobile terminal 100 can also include at least two or more haptic modules154 according to constitution of the mobile terminal.

The projector module 155 is an element for performing an image projectorfunction using the mobile terminal 100. That is, the projector module155 can display an image, which is identical to or partially differentat least from the image displayed on the display 151, on an externalsurface such as a wall or screen according to a control signal of thecontroller 180. In particular, the projector module 155 includes a lightsource generating light (e.g., laser) for projecting an image, an imageproducing unit for producing an image to be projected using the lightgenerated from the light source, and a lens for enlarging the image tobe projected in a predetermined focus distance. In addition, theprojector module 155 can include an adjustment device for adjusting animage projected direction by mechanically moving the lens or the wholemodule.

Further, the projector module 155 can be classified into a CRT (cathoderay tube) module, an LCD (liquid crystal display) module, a DLP (digitallight processing) module or the like according to a device type of adisplay mechanism. In particular, the DLP module is operated by themechanism of enabling the light generated from the light source toreflect on a DMD (digital micro-mirror device) chip and can beadvantageous for the downsizing of the projector module 151. Preferably,the projector module 155 can be provided in a length direction of alateral, front or backside direction of the mobile terminal 100. Theprojector module 155 can also be provided to any portion of the mobileterminal 100.

In addition, the memory 160 stores a program for the operation of thecontroller 180 and temporarily stores input/output data (for example,phone book, messages, still images, moving images, etc.). The memory 160can also store data about vibrations and sounds in various patterns,which are output when a touch input is applied to the touch screen. Thememory 160 can include at least one of a flash memory, a hard disk typememory, a multimedia card micro type memory, a card type memory (forexample, SD or XD memory), a random access memory (RAM), a static RAM(SRAM), a read-only memory (ROM), an electrically erasable programmableROM (EEPROM), a programmable ROM (PROM) magnetic memory, a magnetic diskand an optical disk. The mobile terminal 100 can also operate inrelation to a web storage performing the storing function of the memory160 on the Internet.

Further, the interface 170 serves as a path to all external devicesconnected to the mobile terminal 100. The interface 170 receives data orpower from the external devices and transmits the data or power to theinternal components of the mobile terminal 100 or transmits data of themobile terminal 100 to the external devices. The interface 170 can alsoinclude a wired/wireless headset port, an external charger port, awired/wireless data port, a memory card port, a port for connecting adevice having a user identification module, an audio I/O port, a videoI/O port, an earphone port, etc., for example.

In addition, an identification module is a chip that stores informationfor authenticating the authority to use the mobile terminal 100 and caninclude a user identify module (UIM), a subscriber identify module (SIM)and a universal subscriber identify module (USIM). A device (referred toas an identification device hereinafter) including the identificationmodule can be manufactured in the form of a smart card. Accordingly, theidentification device can be connected to the mobile terminal 100through a port.

Also, the interface 170 can serve as a path through which power from anexternal cradle is provided to the mobile terminal 100 when the mobileterminal 100 is connected to the external cradle or a path through whichvarious command signals input by the user through the cradle to themobile terminal 100. The various command signals or power input from thecradle can be used as a signal for confirming whether the mobileterminal 100 is correctly set in the cradle.

The controller 180 controls the overall operation of the mobileterminal. For example, the controller 180 performs control andprocessing for voice communication, data communication and videotelephony. In FIG. 1, the controller 180 includes a multimedia module181 for playing multimedia. The multimedia module 181 can be included inthe controller 180 or separated from the controller 180. Further, thecontroller 180 can perform a pattern recognition process capable ofrecognizing handwriting input or picture-drawing input applied to thetouch screen as characters or images. In addition, the power supply 190receives external power and internal power and provides power requiredfor the operations of the components of the mobile terminal under thecontrol of the controller 180.

Further, various embodiments of the present invention can be implementedin a computer or similar device readable recording medium usingsoftware, hardware or a combination thereof, for example. According to ahardware implementation, the embodiments of the present invention can beimplemented using at least one of application specific integratedcircuits (ASICs), digital signal processors (DSPs), digital signalprocessing devices (DSPDs), programmable logic devices (PLDs), fieldprogrammable gate arrays (FPGAs), processors, controllers,micro-controllers, microprocessors, electrical units for executingfunctions. The embodiments can also be implemented by the controller180.

According to a software implementation, embodiments such as proceduresor functions can be implemented with a separate software moduleexecuting at least one function or operation. Software codes can beimplemented according to a software application written in anappropriate software language. Furthermore, the software codes can bestored in the memory 160 and executed by the controller 180.

Next, FIG. 2A is a front perspective view of a mobile terminal or ahandheld terminal 100 according to an embodiment of the presentinvention. As shown, the mobile terminal 100 is a bar type terminalbody. However, the present invention is not limited to a bar typeterminal and can be applied to terminals of various types including aslide type, folder type, swing type and swivel type terminals having atleast two bodies that are relatively movably combined.

In addition, the terminal body includes a case (a casing, a housing, acover, etc.) forming the exterior of the terminal 100. In the presentembodiment, the case is divided into a front case 101 and a rear case102. Various electronic components are also arranged in the space formedbetween the front case 101 and the rear case 102. At least one middlecase can be additionally arranged between the front case 101 and therear case 102. The cases can also be formed of plastics throughinjection molding or be made of a metal material such as stainless steel(STS) or titanium (Ti).

In addition, the display 151, the audio output unit 152, the camera 121,user input units 131 and 132 of the user input unit 130 (FIG. 1), themicrophone 122 and the interface 170 are arranged in the terminal body,specifically, in the front case 101. Also, the display 151 occupies mostpart of the main face of the front case 101. The audio output unit 152and the camera 121 are arranged in a region in proximity to one of bothends of the display 151 and the user input unit 131 and the microphone122 are located in a region in proximity to the other end of the display151. In addition, the user input unit 132 and the interface 170 arearranged on the sides of the front case 101 and the rear case 102.

Further, the user input unit 130 is operated to receive commands forcontrolling the operation of the handheld terminal 100 and can includethe operating units 131 and 132. The operating units 131 and 132 can bereferred to as manipulating portions and employ any tactile manner inwhich a user operates the operating units 131 and 132 while havingtactile feeling. The operating units 131 and 132 can also receivevarious inputs. For example, the operating unit 131 receives commandssuch as start, end and scroll, and the second operating unit 132receives commands such as control of the volume of sound output from theaudio output unit 152 or conversion of the display 151 to a touchrecognition mode.

Next, FIG. 2B is a rear perspective view of the mobile terminal 100shown in FIG. 2A according to an embodiment of the present invention.Referring to FIG. 2B, a camera 121′ is additionally attached to the rearside of the terminal body, that is, the rear case 102. The camera 121′has a photographing direction opposite to that of the camera 121 shownin FIG. 2A and can have pixels different from those of the camera 121shown in FIG. 2A. For example, it is preferable that the camera 121 haslow pixels such that it can capture an image of the face of a user andtransmit the image to a receiving part for video telephony, while thecamera 121′ has high pixels because it captures an image of a generalobject and does not immediately transmit the image in many instances.The cameras 121 and 121′ can also be attached to the terminal body suchthat they can be rotated or pop-up.

A flash bulb 123 and a mirror 124 are also arranged in proximity to thecamera 121′. The flash bulb 123 lights an object when the camera 121′takes a picture of the object, and the mirror 124 is used for the userto look at his/her face in the mirror when the user wants toself-photograph himself/herself using the camera 121′. An audio outputunit 152′ is also provided on the rear side of the terminal body. Theaudio output unit 152′ can thus achieve a stereo function with the audiooutput unit 152 shown in FIG. 2A and be used for a speaker phone modewhen the terminal is used for a telephone call.

A broadcasting signal receiving antenna 124 is also attached to the sideof the terminal body in addition to an antenna for telephone calls. Theantenna 124 constructing a part of the broadcasting receiving module 111shown in FIG. 1 can be set in the terminal body such that the antenna124 can be retracted from the terminal body. Further, the power supply190 for providing power to the handheld terminal 100 is set in theterminal body. The power supply 190 can be included in the terminal bodyor detachably attached to the terminal body. A touch pad 135 for sensingtouch is also attached to the rear case 102. The touch pad 135 can be ofa light transmission type as the display 151. In this instance, if thedisplay 151 outputs visual information through both sides thereof, thevisual information can be recognized through the touch pad 135. Theinformation output through both sides of the display 151 can also becontrolled by the touch pad 135. Otherwise, a display is additionallyattached to the touch pad 135 such that a touch screen can be arrangedeven in the rear case 102.

The touch pad 135 also operates in connection with the display 151 ofthe front case 101. The touch pad 135 can be located in parallel withthe display 151 behind the display 151, and can be identical to orsmaller than the display 151 in size.

Turning, next to FIG. 3, which is a flowchart illustrating a method ofcontrolling a mobile terminal according to an embodiment of the presentinvention. In this embodiment, it is assumed that the mobile terminal100 is executing a character inputting function such as a function ofwriting a message (e.g., short text message, multimedia message, email,etc.), a function of inputting a name of a correspondent party in aphonebook list, and a function of inputting a URL, ID, password andsearch word to a text input box of a webpage and the like.

Thus, as shown in FIG. 3, a plurality of key buttons are displayed onthe touchscreen (S31). The display 151 in this embodiment includes atouch screen. Optionally, a hardware type keypad can be provided to themobile terminal 100 to be used when inputting characters. FIG. 4illustrates a touchscreen 400 including a keypad 410 having a pluralityof key buttons which include alphabetic key buttons (e.g., key buttonscorresponding to A to Z) having intrinsic alphabets, respectively.Further, the intrinsic alphabets can include English alphabets, Koreanalphabets (consonants and vowels), Japanese alphabets (hiragana andkatakana) and the like. In the following description, the intrinsicalphabets include English alphabets.

FIG. 4 also illustrates a first key button 411 including an indicator“B” indicating the intrinsic alphabet for this key is the letter “B”.The key buttons of the keypad 410 can also include at least one of asymbol key button, a numeral key button, a space key button, a backspacekey button, an enter key button, etc. In the following description, thekey buttons other than the alphabet key buttons will be referred to as‘additional key buttons’. FIG. 4 also illustrates an input text window460 for displaying text input via the keypad 410.

Next, as shown in FIG. 3, the first key button 411 corresponding to adesired one of the alphabet key buttons is touched by a user (S32), andthen the intrinsic alphabet 13′ of the first key button 411 is input anddisplayed on the input text window 460 (S33). FIG. 4 also illustratesthis feature. Then, with reference to FIG. 3, the controller 180predicts a word based on the first input character (S34) and that isrecommended to the user.

In more detail, embodiments of the present invention provide variousmethods of providing the terminal user with a recommended or predictedword. The following description assumes the recommended word accordingto the input intrinsic alphabet ‘B’ is ‘BEST’. Then, as shown in FIG.5A, the identifier of the intrinsic alphabet ‘B’ displayed on the firstkey button 411 is changed to an identifier of the second alphabet ‘E’ ofthe recommended or predicted word.

Subsequently, referring to FIGS. 3 and 5B, the user can again touch thefirst key button 411 (S35). Then, the second alphabet ‘E’ of thepredicted word is input and displayed on the input text window 460(S36). Subsequently, referring to FIG. 5C, the identifier of the secondalphabet ‘E’ of the predicted word displayed on the first key button 411is changed to an identifier of the third alphabet ‘S’ of the predictedword.

In this manner, the user can easily input a desired word by simplypressing the first key button 411 four times consecutively. After thedesired word has been completely input, the first key button 411 can bechanged back to have the identifier of the intrinsic alphabet ‘B’. Thus,referring to FIGS. 5A to 5C, as the identifier displayed on the firstkey button 441 is changed or converted into a next character of thepredicted word, the user can know in advance which alphabet is to beinput next each time the first key button 441 is touched consecutively.

Next, FIGS. 6A to 6C illustrating an alternative embodiment of informingthe user about what the next character is for the predicted word. Inmore detail, when the user touches the first key button 411corresponding to a desired one of the alphabet key buttons, theintrinsic alphabet ‘B’ of the first key button 411 is input anddisplayed on the input text window 460.

Subsequently, referring to FIG. 6A, a second key button 412corresponding to the second alphabet ‘E’ of the predicted word isdisplayed in a manner of being visually discriminated from the other keybuttons. FIG. 6A illustrates the second key button 412 being displayedin a manner of having a size greater than that of the rest of the keybuttons, by which embodiments of the present invention are non-limited.For example, the second key button 412 can be visually discriminatedfrom other key buttons in a manner of differing in at least one of size,color and style.

Thus, the user can see that if he or she again touches the first keybutton 411, the character “E” will be input. That is, referring to FIG.6B, when the user again touches the first key button 411, the secondalphabet ‘E’ of the predicted word is input and then displayed in theinput text window 460. Referring to FIG. 6C, the second key button 412corresponding to the second alphabet ‘E’ of the predicted word is thenrestored to its original shape. Also, a third key button 413corresponding to a third alphabet ‘S’ of the predicted word is displayedin a manner of being visually discriminated from the other key buttons.

Thus, as shown in FIGS. 6A to 6C, each time the first key button 411 isconsecutively touched, each key button corresponding to an alphabet thatis going to be input next is sequentially displayed in a manner of beingvisually discriminated from the other key buttons. Therefore, the usercan know the next alphabet that is going to be input if they again touchthe first key button 411.

Next, FIGS. 7A to 7C illustrating an alternative embodiment of informingthe user about what the next character is for the predicted word. Asdiscussed previously, when the user first touches the first key button411, the intrinsic alphabet ‘B’ of the first key button 411 is input anddisplayed in the input text window 460.

Referring to FIG. 7A, the controller 180 displays a first indicator 421indicating the second alphabet ‘E’ of the predicted word. In addition,the first indicator 421 is displayed on the first key button 411, bywhich the present invention is non-limited. For example, the firstindicator 421 can be displayed on another spot on the touchscreen 400.

Referring to FIG. 7B, the user again touches the first key button 411and the second alphabet ‘E’ of the predicted word is input and displayedin the input text window 460. Referring to FIG. 7C, the controller 180removes the first indicator 421 indicating the second alphabet ‘E’ ofthe predicted word and displays a second indicator 422 indicating thethird alphabet ‘S’ of the predicted word on the spot from where thefirst indicator 421 was displayed.

Thus, in FIGS. 7A to 7C, each time the user consecutively touches thefirst key button 411, the controller 180 displays indicatorscorresponding to alphabets to be next input. Therefore, the user canknow what alphabet is going to be input next.

Next, FIGS. 8A to 8C illustrating an alternative embodiment of informingthe user about what the next character is for the predicted word. Asdiscussed previously, when the user first touches the first key button411, the intrinsic alphabet ‘B’ of the first key button 411 is input anddisplayed in the input text window 460.

Referring to FIG. 8A, the controller 180 displays the first indicator421 indicating the second alphabet ‘E’ of the predicted word on thefirst key button 411. Subsequently, the user touches the first indicator421 or performs a touch & drag from the first key button 411 to thefirst indicator 421 from (or vice-versa). Then, referring to FIG. 8B,the second alphabet ‘E’ of the predicted word is input and displayed inthe input text window 460. Similarly, the controller 180 displays thesecond indicator 422 indicating the third alphabet ‘S’ of the predictedword on the first indicator 421.

Referring to FIG. 8C, the user touches the second indicator 422 orperforms a touch & drag operation from the first indicator 411 to thesecond indicator 422 (or vice-versa). The third alphabet ‘S’ of thepredicted word is then input and displayed in the input text window 460.Thus, in FIGS. 8A to 8C, each time the user consecutively touches thefirst key button 411, the controller 180 displays indicatorscorresponding to alphabets input next. Therefore, the user can know whatthe next alphabet is going to be input. Moreover, when the neighboringindicators are sequentially touched, the corresponding alphabets can besequentially input.

Next, FIGS. 9A to 9C illustrating an alternative embodiment of informingthe user about what the next character is for the predicted word. Asdiscussed previously, when the user first touches the first key button411, the intrinsic alphabet ‘B’ of the first key button 411 is input anddisplayed in the input text window 460. FIG. 4 shows that the intrinsicalphabet ‘B’ is displayed as a solid line.

Referring to FIG. 9A, the second alphabet ‘E’ of the predicted word isdisplayed in the input text window 460 in a manner of having a styledifferent from that of the input intrinsic alphabet ‘B’, i.e., a dottedline. That is, FIG. 9A shows that the second alphabet ‘E’ of thepredicted word is displayed with a dotted line, while the inputintrinsic alphabet ‘B’ is displayed with a solid line, by which theembodiment of the present invention is non-limited. For example, thesecond alphabet ‘E’ of the predicted word can visually discriminatedfrom the input intrinsic alphabet ‘B’ using different methods such asblinking the alphabet ‘E’, etc.

Subsequently, the user again touches the first key button 411, and thesecond alphabet ‘E’ of the predicted word is input and displayed. Inmore detail, referring to FIG. 9B, the input second alphabet ‘E’ of thepredicted word is displayed with a solid line instead of the previousdotted line. Referring to FIG. 9C, the third alphabet ‘S’ of thepredicted word is then displayed as a dotted line in the input textwindow 460.

Thus, in FIGS. 9A to 9C, each time the user consecutively touches thefirst key button 411, the alphabets to be input next are displayed in ashape different from that of an already input alphabet in the input textwindow 460. Therefore, the user can know what alphabet is going to beinput next.

Next, FIGS. 10A to 10F illustrating an alternative embodiment ofinforming the user about what the next character is for the predictedword. As discussed previously, when the user first touches the first keybutton 411, the intrinsic alphabet ‘B’ of the first key button 411 isinput and displayed in the input text window 460. Again, FIG. 4 showsthat the intrinsic alphabet ‘B’ is displayed as a solid line.

Referring to FIG. 10A, the rest of the alphabets ‘E’, ‘S’ and ‘T’ of thepredicted word except the first input intrinsic alphabet ‘B’ aredisplayed in the input text window 460 in a shape different from that ofthe input intrinsic alphabet ‘B’, i.e., using dotted lines in thisexample. Subsequently, the user again touches the first key button 411,and the second alphabet ‘E’ of the predicted word is input and changedinto a solid line.

That is, referring to FIG. 10B, the input second alphabet ‘E’ isdisplayed in the input text window 460 using a solid line instead of adotted line. Subsequently, the user again touches the key button 411,and the third alphabet ‘S’ of the predicted word is input and displayedwith a solid line as shown FIG. 10C.

Thus, in FIGS. 10A to 10C, when the user touches the key button 441 forthe first time, the rest of the alphabets ‘E’, ‘S’ and ‘T’ of thepredicted word except the input intrinsic alphabet ‘B’ are displayed ina shape different from that of the input intrinsic alphabet ‘B’. Then,each time the user consecutively touches the first key button 411, thecorresponding alphabet is changed from a dotted line to a solid line tohave the same style of the intrinsic alphabet ‘B’.

Meanwhile, referring to FIGS. 10D to 10F, the controller 180 can changean identifier displayed on the first key button 441 according to thepredicted word as soon as the rest of the alphabets of the predictedword are displayed in the input text window 460. In particular, theidentifier of the first key button 411 can be changed to an identifierof an alphabet that is going to be input each time the first key button411 is consecutively touched. Further, not all of the entire rest of thealphabets to be sequentially inputted each time the first key button 411is consecutively touched have to be displayed.

Next, and referring to FIG. 11A, the entire rest of the alphabets ‘E’,‘S’ and ‘T’ of the predicted word except the input intrinsic alphabet‘B’ are displayed in the input text window 460 in a manner of having astyle different from that of the input intrinsic alphabet ‘B’. Inaddition, in this embodiment, the user then touches the displayedpredicted word. Rather than touching the word, the user can alsomanipulate the user input unit. Then, referring to FIG. 11B, the entirerest of the alphabets of the predicted word are simultaneously input anddisplayed in a same style as the intrinsic alphabet ‘B’.

The above descriptions describe the desired word the terminal userintends to input is equal to the predicted word. However, the predictedword is not always equal to the user-desired word. Accordingly, in thefollowing description, a method of inputting the desired word differentfrom the predicted word is explained with reference to FIGS. 12A to 12D.

Further, in the following description, if a desired key button istouched, a corresponding intrinsic alphabet is input. Second orhigher-order alphabets of a predicted word, which can be input if thedesired key button is re-touched, are provided to the user by one of themethods described with reference to FIGS. 5A to 11B. However, forclarity of the following description, the second or higher-orderalphabets of the predicted word are provided to the user by the methoddescribed with reference to FIGS. 5A to 5C.

The following description also assumes the predicted word is ‘BEST’,whereas the desired word is ‘BEAST’. Referring to FIG. 12A, when theuser touches the first key button 411 consecutively twice, the alphabets‘B’ and ‘E’ are sequentially input and displayed in the input textwindow 460. In order to input the desired word, the alphabet ‘A’ shouldbe input next to the already input alphabets ‘B’ and ‘E’. However, ifthe user touches the first key button 411 one more time, the alphabet‘S’ will be input, which is different than the desired word ‘BEAST’.Therefore, the user should not again touch the first key button 411.

Instead, the user touches a fourth key button 414 having the intrinsicalphabet ‘A’. If so, referring to FIG. 12B, the intrinsic alphabet ‘A’of the fourth key button 414 is input. In addition, an identifier of thefirst key button 411 is restored to an identifier of the intrinsicalphabet ‘B’ of the first key button 411.

Based on the input alphabets ‘B’, ‘E’ and ‘A’, the controller 180predicts a desired word the user intends to input. Thus, the controller180 is then able to recommend the predicted word to the user. Again, inthe following description, for clarity, assume that the recommended wordaccording to the input alphabets ‘B’, ‘E’ and ‘A’ is ‘BEAST’.

As the predicted word is predicted, referring to FIG. 12B, an identifierof the intrinsic alphabet ‘A’ displayed on the fourth key button 414 isconverted to an identifier of the fourth alphabet ‘S’ of the predictedword. Subsequently, referring to FIG. 12C, the user again touches thefourth key button 414, and the fourth alphabet ‘S’ of the predicted wordis input and displayed in the input text window 460.

Finally, referring to FIG. 12D, the controller 180 changes theidentifier of the fourth alphabet ‘S’ of the predicted word displayed onthe fourth key button 414 to an identifier of a fifth alphabet ‘T’ ofthe predicted word. In FIGS. 12A to 12D, in case that an alphabet, whichcan be input by repeatedly touching the first key button, becomesdifferent from an alphabet the user intends to input, the user cancorrectly input the alphabet the user intends to input by touchinganother key button having an intrinsic alphabet equal to the alphabetthe terminal user intends to input.

Meanwhile, when the desired word is ‘BBC’, and if ‘B’ is input bytouching the first key button 411, the controller 180 predicts the word‘BEST’. Subsequently, if the first key button 411 is re-touched, thealphabet ‘E’ will be input. Therefore, the desired word ‘BBC’ is notcorrectly input. To solve this problem, the following method is furtherexplained with reference to FIG. 13A and FIG. 13B.

Referring to FIG. 13A, if the user touches the first key button 411, theintrinsic alphabet ‘B’ of the first key button 411 is input. The inputintrinsic alphabet ‘B’ is also displayed in the input text window 460,for example. Moreover, an identifier of the second alphabet ‘E’ of thepredicted word ‘BEST’ is displayed on the first key button 411.

In this instance, a double-touch or a long touch is performed on thefirst key button 411. Further, FIG. 13A shows that the first key button411 is double touched. If so, referring to FIG. 13B, the intrinsicalphabet ‘B’ of the first key button 411 is input instead of the secondalphabet ‘E’ of the predicted word ‘BEST’ displayed on the first keybutton 411. The input intrinsic alphabet ‘B’ is further displayed in theinput text window 460.

Based on the input alphabets ‘B’ and ‘B’, the controller 180 predicts adesired word the user intends to input. The controller 180 is then ableto recommend the predicted word to the user. In the followingdescription, for clarity, the predicted word according to the inputalphabets ‘B’ and ‘B’ is ‘BBC’. Finally, an identifier of the thirdalphabet ‘C’ of the predicted word ‘BBC’ is displayed on the first keybutton 411.

The following description describes another method of inputting thedesired word ‘BBC’ with reference to FIGS. 14A to 14D. Referring to FIG.14A, if the user touches the first key button 411, the intrinsicalphabet ‘B’ of the first key button 411 is input and displayed in theinput text window 460, for example. Moreover, the controller 180displays an identifier of the second alphabet ‘E’ of the predicted word‘BEST’ on the first key button 411.

Also, assume the user does not touch the keypad 410 during a prescribedperiod of time (e.g., 0.5 second, 1 second, etc.). If so, the controller180 controls each corresponding identifier of all alphabet key buttonsof the keypad to be restored to identifiers of the original intrinsicalphabets. Therefore, referring to FIG. 14B, an identifier of the secondalphabet ‘E’ of the recommended word ‘BEST’ displayed on the first keybutton 411 is changed to an identifier of an intrinsic alphabet ‘B’ ofthe first key button 411.

Referring to FIG. 14C, the user re-touches the first key button 411.Then, the intrinsic alphabet ‘B’ of the first key button 411 is inputand displayed in the input text window 460. Further, the controller 180predicts the recommended word ‘BBC’ based on the input alphabets ‘B’ and‘B’. Therefore, referring to FIG. 14D, an identifier of the thirdalphabet ‘C’ of the recommended word ‘BBC’ is displayed on the first keybutton 411.

Further, in FIGS. 14A to 14D, if the keypad is not touched during aprescribed period of time, each corresponding identifier of all alphabetkey buttons of the keypad is restored to an identifier of the originalintrinsic alphabet. The following description explains another case thateach corresponding identifier of all alphabet key buttons of the keypadis restored to an identifier of an original intrinsic alphabet withreference to FIGS. 15A and 15B.

Referring to FIG. 15A, the alphabets ‘B’ and ‘B’ are displayed in theinput text window 460. In addition, an identifier of a third alphabet‘C’ of the predicted word ‘BBC’ is displayed on the first key button411. Further, one of the additional key buttons is touched by the user.In FIG. 15A, the user touches a ‘space’ key button 415.

If so, referring to FIG. 15B, the space is input to the mobile terminal100, and the identifier of the third alphabet ‘C’ of the predicted word‘BBC’ displayed on the first key button 411 is converted to anidentifier of the intrinsic alphabet of the first key button 411.

Referring to FIG. 16A, if the user touches the first key button 411, theintrinsic alphabet ‘B’ of the first key button 411 is input anddisplayed in the input text window 460, for example. Moreover, anidentifier of the second alphabet ‘E’ of the predicted word ‘BEST’ isdisplayed on the first key button 411.

In this instance, the user performs a double-touch or a long touchoperation on the first key button 411. FIG. 16A shows the user longtouching the first key button 411. If so, referring to FIG. 16B, a firstpriority predicted word ‘BEST’ according to the input intrinsic alphabet‘B’ is displayed on the touchscreen 400.

Subsequently, the user performs a simple or single touch, which isneither a double touch nor a long touch, on the first key button 411instead of the double or long touch. If so, referring to FIG. 16C, asecond priority predicted word ‘BEAST’ according to the input intrinsicalphabet ‘B’ is displayed on the touchscreen 400. Subsequently, the userperforms a double or long touch operation on the first key button 411.FIG. 16C shows the user long touching the first key button 411.Alternatively, the second priority predicted word ‘BEAST’ is touched onthe touchscreen 400.

If so, referring to FIG. 16D, the second priority predicted word ‘BEAST’is input. Further, in FIGS. 16A to 16D, the predicted words aredisplayed one by one, by which the present embodiment is non-limited.For example, a plurality of predicted words including the first andsecond priority predicted words can be simultaneously displayed. Then,if one of the displayed predicted words is touched, for example, theselected predicted word is input.

In addition, FIG. 16B also illustrates an indicator 490 being displayedon the key button 411. In this embodiment, the user can select theindicator 490 to view a list of predicted words. The user can thenselect one predicted word that matches their desired word. The predictedwords may also be displayed one at a time or be displayed in a listformat. The indicator 490 can also be displayed anywhere on the touchscreen such as in the display portion 460. A pop-up window can also bedisplayed that includes the list of predicted words.

In addition, the controller 180 can predict words the user intends toinput based on previously input words, based on common words, based onwords in a dictionary, based on predetermined words set by a user, etc.Thus, once the user enters the first character, the controller 180 cansearch words stored in the memory and provide the user with one or morepredicted words.

Accordingly, the present invention provides several advantages. Forexample, according to at least one of the embodiments of the presentinvention, the user can easily input characters via a keypad on themobile terminal having key buttons of which number or size is smallerthan that of key buttons provided to a keyboard of a personal computer.

In addition, the above-described methods can be implemented in a programrecorded medium as computer-readable codes. The computer-readable mediainclude all kinds of recording devices in which data readable by acomputer system are stored. The computer-readable media include ROM,RAM, CD-ROM, magnetic tapes, floppy discs, optical data storage devices,and the like for example and also include carrier-wave typeimplementations (e.g., transmission via the Internet). In addition, thecomputer can include the controller 180 of the terminal.

It will be apparent to those skilled in the art that variousmodifications and variations can be made in the present inventionwithout departing from the spirit or scope of the inventions. Thus, itis intended that the present invention covers the modifications andvariations of this invention provided they come within the scope of theappended claims and their equivalents.

What is claimed is:
 1. A digital television comprising: a display unitconfigured to display a keypad including a plurality of key buttonswhich are assigned with different alphabet characters, respectively, anda text window; and a controller configured to: receive a first signalselecting a first key button of the plurality of key buttons, display afirst alphabet character assigned with the first key button in the textwindow, and display a first sub key button assigned with a secondalphabet character on a region adjacent to the first key button of thekeypad, in response to the first signal, the first sub key buttonpartially overlapping a second key button neighboring to the first keybutton, receive a second signal selecting the first sub key button, anddisplay the second alphabet character next to the first alphabetcharacter in the text window, and display a second sub key buttonassigned with a third alphabet character on the same region adjacent tothe first key button of the keypad, in response to the second signal,the second sub key button partially overlapping the same second keybutton neighboring to the first key button, wherein the second alphabetcharacter is predicted as a next character of the first alphabetcharacter, and wherein the third alphabet character is predicted as anext character of the first and second alphabet characters.
 2. Thedigital television of claim 1 further comprising a memory, wherein thesecond and third alphabet characters are extracted from the memory. 3.The digital television of claim 2, wherein the second alphabet characteris extracted from the memory based on a first word related to the firstalphabet character.
 4. The digital television of claim 2, wherein thethird alphabet character is extracted from the memory based on a secondword related to both the first and second alphabet characters.
 5. Thedigital television of claim 3, wherein the first word is the same as thesecond word.
 6. The digital television of claim 4, wherein the firstword is the same as the second word.
 7. The digital television of claim3, wherein the controller is configured to display the first sub keybutton together with information about the first word on the displayunit.
 8. The digital television of claim 7, wherein the controller isconfigured to: receive a third signal selecting the information aboutthe first word, and display the rest of the alphabet characters of thefirst word at the same time such that the rest of the alphabetcharacters are displayed next to the first and second alphabetcharacters in the text window.
 9. The digital television of claim 1,wherein the controller is configured to concurrently display both thefirst sub key button assigned with the second alphabet character and athird key button assigned with the same second alphabet character. 10.The digital television of claim 1, wherein the controller is configuredto concurrently display both the second sub key button assigned with thethird alphabet character and a fourth key button assigned with the samethird alphabet character.
 11. The digital television of claim 1, whereinthe controller is configured to: display the first and second alphabetcharacters in the text window as a first style, and display the rest ofthe alphabet characters in the text window as a second style differentfrom the first style.
 12. A method of controlling a digital television,the method comprising: displaying, via a display unit, a keypadincluding a plurality of key buttons which are assigned with differentalphabet characters, respectively, and a text window; receiving, via acontroller, a first signal selecting a first key button of the pluralityof key buttons; displaying, via a controller, a first alphabet characterassigned with the first key button in the text window, and displaying afirst sub key button assigned with a second alphabet character on aregion adjacent to the first key button of the keypad, in response tothe first signal, the first sub key button partially overlapping asecond key button neighboring to the first key button; receiving, via acontroller, a second signal selecting the first sub key button; anddisplaying, via a controller, the second alphabet character next to thefirst alphabet character in the text window, and displaying a second subkey button assigned with a third alphabet character on the same regionadjacent to the first key button of the keypad, in response to thesecond signal, the second sub key button partially overlapping the samesecond key button neighboring to the first key button, wherein thesecond alphabet character is predicted as a next character of the firstalphabet character, and wherein the third alphabet character ispredicted as a next character of the first and second alphabetcharacters.
 13. The method of claim 12, further comprising a memory,wherein the second and third alphabet characters are extracted from thememory.
 14. The method of claim 13, wherein the second alphabetcharacter is extracted from the memory based on a first word related tothe first alphabet character, and the third alphabet character isextracted from the memory based on a second word related to both thefirst and second alphabet characters.
 15. The method of claim 14,wherein the first word is the same as the second word.
 16. The method ofclaim 14, further comprising: displaying the first sub key buttontogether with information about the first word on the display unit. 17.The method of claim 16, further comprising: receiving a third signalselecting the information about the first word; and displaying the restof the alphabet characters of the first word at the same time such thatthe rest of the alphabet characters are displayed next to the first andsecond alphabet characters in the text window.
 18. The method of claim12, further comprising: concurrently displaying both the first sub keybutton assigned with the second alphabet character and a third keybutton assigned with the same second alphabet character.
 19. The methodof claim 12, further comprising: concurrently displaying both the secondsub key button assigned with the third alphabet character and a fourthkey button assigned with the same third alphabet character.
 20. Themethod of claim 16, further comprising: displaying the first and secondalphabet characters in the text window as a first style; and displayingthe rest of the alphabet characters in the text window as a second styledifferent from the first style.